The present disclosure relates to a multilayer ceramic capacitor and a board for mounting thereof.
As electronic components using a ceramic material, there are capacitors, inductors, piezoelectric elements, varistors, thermistors, and the like.
Among these ceramic electronic components, a multilayer ceramic capacitor (MLCC) has advantages such as a small size, high capacitance, and easiness of mounting and has been usefully used as a decoupling capacitor disposed in a high frequency circuit such as a power supply circuit of a large scale integration circuit (LSI), or the like.
In this case, stability of the power supply circuit depends on equivalent serial inductance (ESL) of the multilayer ceramic capacitor. Particularly, stability of the power supply circuit is high at relatively low ESL.
Therefore, in order to stabilize the power supply circuit, the multilayer ceramic capacitor should have lower ESL, and as an electronic device has been used at a high frequency and high current, the demand for low ESL has further increased.
In addition, the multilayer ceramic capacitor is used as an electromagnetic interference (EMI) filter in addition to the use thereof as the decoupling capacitor. In this case, in order to improve high frequency noise removal and attenuation characteristics, ESL is required to be lower.
Some of three-terminal type capacitors having a structure in which internal electrodes are vertically disposed on a board mounting surface and dielectric layers formed using a ceramic material and internal electrodes formed using a metal are alternately stacked in order to decrease ESL have been disclosed.
However, in the case of the three-terminal type multilayer ceramic capacitor, adhesion strength between a ground terminal formed in a central portion of the ceramic body and the ceramic body is relatively low, such that reliability of a product may be deteriorated.
Meanwhile, since the dielectric layers of the multilayer ceramic capacitor have piezoelectricity and electrostriction, when a direct current (DC) voltage or an alternating current (AC) voltage is applied to the multilayer ceramic capacitor, a piezoelectric phenomenon may occur between internal electrodes, causing the occurrence of vibrations.
This vibration is transferred to a board on which the multilayer ceramic capacitor is mounted through an external electrode of the multilayer ceramic capacitor, such that the entirety of a board acts as a sound reflective surface to generate a vibration sound, noise.
Such a vibration sound may have a frequency corresponding to an audio frequency in a region of 20 to 20,000 Hz giving an unpleasant feeling to listeners, and is known as acoustic noise.